This invention relates to an orthopedic padding, for example for use as an undercast liner of the type used to protect and cushion the skin of a patient from the relatively rigid material of a cast, such as those constructed of plaster of Paris or synthetic cast tape. The liner allows the patient to carry out routine activities such as bathing, showering, swimming, and the like without fear of the liner getting wet.
Traditional cast padding is constructed from a simple stockinette and padding material made from cotton or synthetic fibers, and offers poor or no water resistant capability. Cotton and some synthetic paddings actually absorb and retain large quantities of water. A cast is typically worn for a period of 6-8 weeks. During this period of time, traditional casts having a water-absorbent stockinette can promote skin maceration, discomfort. Traditional cast paddings can also breed odor causing bacteria as perspiration and water from washing and bathing migrates to and through the stockinette. The stockinette remains wet or damp for an extended period of time, causing the problems mentioned above.
The present invention provides a more conformable, water-resistant liner at a reduced cost as compared to water resistant products already available in the market. The present invention is directed to a construction that overcomes the drawbacks of water-resistant undercast liners such as that found in U.S. Pat. Nos. 5,102,711 and 5,277,954. For example, the monofilament structure of the liner has higher elongation in the width direction and provides a higher stretch during application that results in a better conforming liner which can be easily molded around a limb. Due to the improved padding/cushioning as compared to other liner and padding products known in the prior art, the undercast liner of the present invention requires fewer layers during application. The present invention may also have an adhesive coating incorporated on either or both surfaces. The tacky surface, when applied away from the skin, adheres to itself sufficiently to form a smoother underlayer for a cast. Additionally, it provides a non-slip effect under the cast tape and keeps the liner in position to facilitate easier application of the cast tape.
One of the problems with conventional cast padding as well as commercially available water resistant padding is that the padding collapses underneath a cast over the duration of 4-6 weeks as water and perspiration are absorbed into the structure. This reduction in thickness and resultant increase in density retards moisture transfer by both wicking and evaporation, and lessens the protection offered by the padding.
A water-resistant undercast liner such as disclosed and claimed in this application can help alleviate skin maceration problems which generally require additional treatment or therapy and eliminates the need for frequent cast changes. The present invention accommodates bathing, showering and contact with water without significant penetration of water into the padding, therefore keeping the skin relatively dry. In addition, the padding of the present invention provides improved conformability, cushioning, breathability, ease of application and a low profile as compared to a traditional undercast liner.
One embodiment of the invention uses a knitted spacer fabric having highly resilient monofilament yarns that allow the padding to keep its shape and loft when applied under an orthopedic cast. This feature also ensures less layers are needed than typical paddings used in this field. The materials and structure of the present invention offer excellent drainage and drying properties due to low surface area and low surface energy. The present invention can be used with an adhesive applied to one side, away from the skin, that permits a more effective non-slip effect, however, the knitted spacer material can be used with no adhesive layer.
The present invention is a very cost effective method of avoiding skin maceration problems arising from wearing an orthopedic cast over a period of weeks. The present invention will avoid the need for frequent cast changes arising for getting the orthopedic cast and padding wet. The present invention affords the opportunity to shower and bath and keep the skin clean with water without damaging the padding and also allows removal of the orthopedic cast using a cast saw without fear of cutting through the padding so improving comfort and safety.